EGLN3 and head and neck squamous cell carcinoma: We observed a higher DNA methylation level of the HIF1A promoter region in normal tissues compared to tumors (p = 0.002) and, on the contrary, higher DNA methylation in promoter regions of EGLN2 and EGLN3 (p = 0.04 and p < 0.0001) in HNSCC tumor tissues.